Generation of a depth map for an image

Abstract

An apparatus for generating an output depth map for an image comprises a first depth processor ( 103 ) which generates a first depth map for the image from an input depth map. A second depth processor ( 105 ) generates a second depth map for the image by applying an image property dependent filtering to the input depth map. The image property dependent filtering may specifically be a cross-bilateral filtering of the input depth map. An edge processor ( 107 ) determines an edge map for the image and a combiner ( 109 ) generates the output depth map for the image by combining the first depth map and the second depth map in response to the edge map. Specifically, the second depth map may be weighted higher around edges than away from edges. The invention may in many embodiments provide a temporally and spatially more stable depth map while reducing degradations and artifacts introduced by the processing.

1 . An apparatus for generating an output depth map for an image, the apparatus comprising:
 a first depth processor for generating a first depth map for the image from an input depth map;   a second depth processor for generating a second depth map for the image by applying an image property dependent filtering to the input depth map;   an edge processor for determining an edge map for the image; and a combiner for generating the output depth map for the image by combining the first depth map and the second depth map in response to the edge map where the combiner is arranged to weigh the second depth map higher in edge regions than in non-edge regions, and edge processor is arranged to determine the edge map in response to an edge detection process performed on the image.   
     
     
         2 . (canceled) 
     
     
         3 . The apparatus of  claim 1  wherein the combiner is arranged to weigh the second depth map higher than the first depth map in at least some edge regions. 
     
     
         4 . The apparatus of  claim 1  wherein the image property dependent filtering comprises at least one of:
 a guided filtering; 
 a cross-bilateral filtering; 
 a cross-bilateral grid filtering; and 
 a joint bilateral upsampling. 
 
     
     
         5 . The apparatus of  claim 1  wherein the edge processor is arranged to determine the edge map in response to an edge detection process performed on at least one of the input depth map and the first depth map. 
     
     
         6 . (canceled) 
     
     
         7 . The apparatus of  claim 1  wherein the combiner is arranged to generate an alpha map in response to the edge map; and to generate the third depth map in response to a blending of the first depth map and the second depth map in response to the alpha map. 
     
     
         8 . The apparatus of  claim 1  wherein the second depth map is at a higher resolution than the input depth map. 
     
     
         9 . A method of generating an output depth map for an image, the method comprising:
 generating a first depth map for the image from an input depth map;   generating a second depth map for the image by applying an image property dependent filtering to the input depth map;   determining an edge map for the image;   generating the output depth map for the image by combining the first depth map and the second depth map in response to the edge map, and wherein generating the output depth map comprises weighting the second depth map higher in edge regions than in non-edge regions and the edge map is determined in response to an edge detection process performed on the image.   
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 9  wherein generating the output depth map comprises weighing the second depth map higher than the first depth map in at least some edge regions. 
     
     
         12 . The method of  claim 9  wherein the image property dependent filtering comprises at least one of:
 a guided filtering; 
 a cross-bilateral filtering; 
 a cross-bilateral grid filtering; and 
 a joint bilateral upsampling. 
 
     
     
         13 . (canceled) 
     
     
         14 . The apparatus of  claim 9  wherein the second depth map is at a higher resolution than the input depth map. 
     
     
         15 . A computer program product comprising computer program code means adapted to perform all the steps of  claim 9  when said program is run on a computer.